Restructuring Restructuring (Details Textual) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 12.0	$ 0.9	$ 33.1
2017 Corporate Strategy
Restructuring Cost and Reserve [Line Items]
Other Nonrecurring Expense	$ 135.0
Resources Redirected through Restructuring Program	$ 400.0
Charges Recognized Under Our 2017 Corporate Strategy Restructuring Program			22.9	19.4
2016 Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges					17.7
2015 Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges					8.0
Cambridge, MA
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation					$ 45.5
Cambridge, MA | 2016 Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 7.4
Restructuring charges | 2017 Corporate Strategy
Restructuring Cost and Reserve [Line Items]
Restructuring charges			12.0	0.9
Selling, General and Administrative Expenses [Member] | 2017 Corporate Strategy
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 10.9	$ 18.5